Volcanic glass in Cretaceous dacites and rhyolites of the Paraná Magmatic Province, southern Brazil: Characterization and quantification by XRD-Rietveld - Andrade, Fábio Ramos Dias de; Polo, Liza; Janasi, Valdecir de Assis; Carvalho, Flavio Machado de Souza (Journal of Volcanology and Geothermal Research, 2018)